In rectangular balers bales are formed by compressing crop material in a bale chamber or bale case by a plunger which is reciprocable with the bale chamber. At the end of a baling session one or more bales may be left in the bale chamber, and it may be desirable to remove those one or more bales from the bale chamber. To that end it is known to provide an ejection system in the bale chamber. Such an ejection system comprises one or more reciprocable shuttle assemblies each provided with bale engaging means, also called dogs or tines adapted to engage in the bale when the corresponding shuttle assembly moves in a forward direction and to disengage the bale when the shuttle assembly moves in a backward direction.
An example of an ejection system with one shuttle assembly is disclosed in EP 0 264 497 B1 in the name of the Applicant. An example with two shuttle assemblies is disclosed in EP 2 108 246 B1 in the name of the Applicant.
The provision of a second shuttle assembly which reciprocates near the discharge outlet of the bale chamber has the advantage that the bale(s) nearest the discharge outlet can be ejected in an improved way. WO 2011/042332, also in the name of the Applicant discloses an advantageous dog for use in an ejector system.
The bale engaging means, also called dogs or tines may be freely rotatable around a pivot point in the shuttle assembly, see e.g. EP 0 264 497 B1, EP 2 108 246 B1 and WO 2011/042332. Alternatively, the dogs may be spring-biased such as in U.S. Pat. No. 5,540,144 and NL 8801271. Further, U.S. Pat. No. 7,093,537 discloses an ejector system using a first lath and a second lath arranged above each other. The conveyor elements or dogs are connected pivotally to both laths. During operation the cylinder will first move one lath with respect to the other lath to bring the dogs in an extended position to engage in the bale, whereupon both laths are moved together to advance the bale.
The problems with the ejector systems of the prior art are:                slippage may occur during the first strokes of the shuttle assembly due to the fact that the projecting tips of the dogs do not properly engage in the bales. This may lead to damage of the bales; and/or        the complexity of the system; and/or        the lack of robustness.        